Last January, Sen. John McCain led a delegation along with his longtime sidekick, Sen. Lindsey Graham, to a contingent of Ukrainian troops not far from the front line in eastern Ukraine. In the presence of Ukrainian President Petro Poroshenko, Graham told the soldiers: "Your fight is our fight … 2017 will be the year of offense. All of us will go back to Washington and we will push the case against Russia."

McCain promised the assembled troops, "we will do everything we can to provide you with what you need to win."

When contemplating the long careers of the two Republican senators, it is hard to escape the conclusion that McGeorge Bundy's quip about the famed Cold War columnist Joe Alsop – that he had "never known him to go to any area where blood could be spilled that he didn't come back and say more blood" – applies equally to McCain and Graham.